Characterization and Control of Structure, Energetics and Electrical Properties at Interfaces between Perovskite Active Layers and Charge-Collection Electrodes

非技术描述：该项目侧重于电极和新材料（钙钛矿）之间形成的界面的表征和控制，这些材料在新的太阳能电池平台中作为活性层显示出巨大的前景。这样的平台有潜力成为廉价、地球资源丰富的太阳能发电替代品。开发新型能量转换平台的关键挑战之一是理解和优化活性层材料与电触点之间的电荷转移。该项目开发了新的测量方法，以了解电接触附近有源层的结构，以及这种结构如何影响最终控制能量转换效率的电性能。该项目还为亚利桑那大学的研究生和亚利桑那科学、工程和数学学者（ASEMS）项目的本科生提供培训机会，该项目主要针对少数民族、低收入家庭和第一次上大学的家庭的学生。联合首席研究人员还继续与亚利桑那州普雷斯科特的亚瓦派社区学院合作，为大一和大二学生提供“入门”研究经验。技术描述：本项目重点研究金属卤化物钙钛矿、杂化活性层材料和电触点之间的界面的物理、能量和电性能非均质性的纳米尺度表征和控制。这些界面是探索新兴薄膜太阳能转换平台中电荷收集或注入的模型系统。该项目包括：a)控制原型电触点和电荷选择中间层中的界面组成，利用具有末端官能团的自组装单层“模板”生长钙钛矿活性层；b)通过高灵敏度紫外光发射光谱和高分辨率、角度分辨的x射线光发射，表征价带能和能量色散作为有源层结构的函数；C)利用基于波导的光谱电化学技术探测有源层中的导带能量和由成分和结构非均质性引起的带边缘能量的色散；D)利用导电尖端原子力显微镜表征10- 100nm长度尺度下接触/有源层异质结的电学性质，以绘制电学性质的非均质性。这项基础研究可以揭示电荷转移机制，并最终在新兴的太阳能电池平台上实现高效的能量转换。

Nontechnical Description: This project focuses on the characterization and control of the interfaces formed between electrodes and new materials (perovskites) that have shown great promise as active layers in new solar cell platforms. Such platforms have potential as inexpensive, earth-abundant alternatives for production of electricity from sunlight. One of the key challenges in the development of new energy conversion platforms is the understanding and optimization of the transfer of electrical charges between the active layer material and the electrical contacts. This project develops new measurement approaches in order to understand the structure of the active layer near the electrical contact, and how this structure influences electrical properties that ultimately control energy conversion efficiency. The project also provides opportunities for training of graduate students at the University of Arizona and for undergraduate students from the AZ Science, Engineering, and Math Scholars (ASEMS) Program, which focuses on students from minority populations, low-income households, and families where the student is the first to attend college. The co-principal investigators also continue a partnership with Yavapai Community College in Prescott, Arizona - providing "gateway" research experiences for freshman and sophomores.Technical Description: This project focuses on the nanometer-scale characterization and control of physical, energetic and electrical property heterogeneity, across interfaces between metal halide perovskites, as well as hybrid active layer materials, and electrical contacts. These interfaces are model systems to explore charge collection or injection in emerging thin-film solar energy conversion platforms. The project includes: a) control of interface composition in prototype electrical contacts and charge selective interlayers, using self-assembled monolayers with terminal functional groups that "template" growth of perovskite active layers; b) characterization of valence band energies and energetic dispersion as a function of active layer structure via high-sensitivity UV-photoemission spectroscopies and high-resolution, angle-resolved X-ray photoemission; c) probing conduction band energies in the active layer and dispersion in band edge energies arising from compositional and structural heterogeneity, using waveguide-based spectroelectrochemical techniques; d) characterization of the electrical properties of contact/active layer heterojunctions at 10-100 nm length scales using conducting-tip atomic force microscopy to map heterogeneity in electrical properties. This fundamental study could reveal the charge transfer mechanisms and ultimately lead to efficient energy conversion in the emerging solar cell platforms.